1. Field of the Invention
The present invention relates in general to a mechanism for vibrating a pattern plate to thereby remove the pattern plate from a mold formed by a mold making machine. More particularly, this invention is concerned with an improved pattern-plate removing mechanism which permits easy and fast changing of a pattern plate from one kind to another.
2. Discussion of the Prior Art
There is known a mold making machine adapted to compact a mass of sand within a molding flask, thereby preparing a casting mold. One type of this mold making machine uses a pattern plate and a pair of flasks (upper and lower flasks) which are superposed on each other such that the pattern plate is interposed between the flasks. The pattern plate has an integrally formed pattern and cooperates with the flasks to define upper and lower mold cavities, which are filled with sand to form upper and lower halves of a casting mold. The upper and lower flasks are then separated from each other while the pattern plate is removed from the prepared molds. Thus, the casting mold consisting of the upper and lower halves is prepared.
In the known mold making machine of the type indicated above, a vibrator is usually attached to the pattern plate, to oscillate or vibrate the pattern plate thereby removing the pattern plate from the prepared mold halves in the mold cavities, upon separation of the upper and lower flasks, while protecting the mold against chipping or other defects which may occur due to adhesion of the pattern of the pattern plate to the mold surfaces.
The pattern-plate removing mechanism using the vibrator directly attached to the pattern plate requires cumbersome and time-consuming changeover when the mold to be prepared by the mold making machine is changed from one kind to another. Namely, it is necessary to remove the vibrator from the pattern plate for one kind of mold, and attach the vibrator to another pattern plate for the new mold to be prepared. Thus, the known mold making machine using this mechanism for removing the pattern plate suffers from low production efficiency, particularly when the same machine is used to prepare different kinds of molds using different pattern plates.
To improve the production efficiency, it is proposed to attach an appropriate vibrator to the newly used pattern plate while another vibrator is used on the machine. However, this procedure requires two or more vibrators, inevitably resulting in an increase in the overall machine cost. Further, the above procedure still requires the attachment and removal of the vibrators to and from the pattern plates, which involve disconnection and re-connection of the vibrators to and from an electric or pneumatic power source. Thus, the proposed procedure still suffers from low efficiency of setup changeover for different kinds of molds.